I am using the backup facility in Kaspersky Total Security 21.3.10.391 running on Windows 10, backing up to an external 1Tb USB drive and have the same issue. It appears to be dependent upon the number of files backed up. I have one backup which contains approximately 44000 files and recovery works fine, displaying the file tree structure and allowing me to select and restore a single file. I have another backup containing approximately 66000 files and, as with the original poster, when I try to restore I only get a check box with 'ALL FILES' in. Incidentally, the reason I have more than one backup file is because I came across this problem previously and thought I'd solved it by splitting my backup into 5 smaller tasks. This worked ok until one of the backup tasks again exceeded what I assume is the maximum number of files. I don't understand why there would be a maximum file number. The previous solution doesn't help as I can't see the individual files to select.